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341.
ABSTRACT

Canada has benefited more than most countries from the advantage of its geography, but proximity to the United States has created a cocoon of complacency on trade and security that is no longer assured. This makes the key question about the future of Canada-US relations whether the erratic “America First” impulses of Donald Trump will persist after he leaves the White House. If nationalist populism takes root, self-interest will prevail and the special partnership for Canada with the United States will fade. This essay considers the notion of privilege that served Canada well for decades as one that can no longer be taken for granted. Canada must take realistic actions to defend and advance its own interests. This will reflect the confidence and maturity of a nation fully aware of its capabilities and the limitations of its global potential.  相似文献   
342.
Malinky, J.M. & Geyer, G., 6 March 2019. Cambrian Hyolitha of Siberian, Baltican and Avalonian aspect in east Laurentian North America: taxonomy and palaeobiogeography. Alcheringa 43, 171–203. ISSN 0311-5518.

Newly identified hyoliths from early Cambrian ‘Small Shelly Fossil’ assemblages in New York State and Quebec extend the geographical ranges of hyolith taxa, otherwise known only from Baltica and Siberia, into eastern Laurentian North America, and in some cases, are accompanied by significant stratigraphical range extensions. The newly recognized taxa from this region include the hyolithids Hexitheca washingtonensis sp. nov., Aimitus sp., A. sp. cf. A. communis, Anabaricornus sp., Similotheca americana, Grantitheca glenisteri, and the orthothecids Decoritheca sp., Contitheca sp., two species of Holmitheca, and two hyolith species that can not be confidently assigned to an order at this time. Early Cambrian limestone clasts within the Lower Ordovician of Quebec have produced the hyolithids Similotheca americana and Nevadotheca princeps. The occurrences of Aimitus, Anabaricornus, and Holmitheca provide a palaeobiogeographical link with hyolith assemblages in Siberia, and Hexitheca to Baltica. Contitheca not only is known from these areas, but also has been found in west Laurentia, Morocco, Korea and Antarctica. A review of previously named species demonstrates that none of their type materials can be confidently referred to genus or species level because of poor preservation.

John M. Malinky [], Department of Physical Science, San Diego City College, 1313 Park Boulevard, San Diego, CA 92101, USA; Gerd Geyer* [], Institut für Geographie und Geologie, Bayerische Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.  相似文献   

343.
The woodchuck, Marmota monax, a burrowing scuirid of eastern North America, was a common food animal of prehistoric peoples. Since the species has a single, brief birthing period all juveniles are at a comparable stage of development at a given time. Widths of the continuously growing incisors, development of the cheek teeth and alveoli, and loss of deciduous teeth have been determined from a sample with known dates of collection. These data are compared to juvenile woodchuck remains from an archaeological site to determine season of kill.  相似文献   
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